Wonderland is a world from the Disney movie Alice in Wonderland. The various characters featured in the world are taken from the film. Unlike most other worlds in the game, you will not have an extra optional party member to match the world.
Sora, Donald and Goofy float into Wonderland, and are immediately passed by a running rabbit with a watch. He says to himself that he's late, and the Queen will "have his head" for sure. From where you start, go to the door to be led to the next room, where you'll see the rabbit, still running.
The rabbit then goes through a small door, disappearing from view. The group is mystified as to how he had gotten small enough to go through the door, and the doorknob then starts to talk, much to the surprise of the three. Sora asks the doorknob how the rabbit had gotten so small, and a table and chair appear in the middle of the room, along with two bottles sitting on top of the table. Before drinking from one of the bottles, push the bed into the wall. Afterward, go near the bottles and press "Drink". Sora will drink from the blue bottle, and the whole party will shrink. After shrinking, jump off the table and fight the Heartless that come to you. Go through the passageway next to the door to be taken to the Queen's Court.
The next cutscene will give you a new task - find evidence to prove Alice is innocent. There are four different clues scattered around the area - two in the Bizarre Room, with alternate entrances accessed through Lotus Forest, and two in Lotus Forest.
After entering the forest and being greeted by the mysterious Chesire Cat, head forward to start looking for the clues.
Once you find all 4 pieces of evidence, you will learn Blizzard earlier than you would have otherwise.
After collecting your evidence, go back to the Queen's Court. Go up to one of the cards and tell them you're ready. If you collect all four pieces of evidence, the Queen will only have one piece of evidence. If you collect three pieces of evidence, the Queen will have two pieces of evidence. Her evidence depends on how much evidence you have. After she shuffles the clues, you will be told to choose one. The more evidence you have, the bigger your chance is of getting your own clue. After choosing a clue, you'll have to fight the Queen to save Alice.
After the battle, go back to the Lotus Forest to be greeted once again by the Chesire Cat. In the Lotus forest, feed the yellow flower another potion to grow large. Slide the nearby boulder into the pond to raise two lily pads. Hit the big tree to access the nut again, and choose to take it. Before eating it, hit the tree again to keep it facing away from you. Now eat the acorn to shrink back to small size.
Back at the pond, use the newly raised lily pads to access a closed off area and enter the nearby door to find yourself back in the Queen's Court.
Open the treasure chest.
Back in the forest, head to the back again, and jump on the mushrooms (use the larger mushroom on the left) to reach the branch with the acorn. From here, enter the nearby door set into the leafy canopy to enter the Bizarre Room.
The whole room has been turned on its side! Examine the shelf with the teddy bear, and attack the latch to make the shelf drop the bear. This affects events a bit later. Check the first lamp to light it, and you will receive a chest, open it. When you light the second lamp, a picture appears. Examine this to reenter another closed off section of the Lotus Forest.
Go to the entrance, and jump up the mushrooms in the alcove. Head up toward the door above the entrance, and you will exit back out into Bizarre Room, this time on the other wall.
Turn the faucet to make the pot become real, and jump into it to return to the Queen's Court.
Open the chest. Go through the Bizarre entrance.
In the Bizarre Room (right-side up) grow big again and read the book that appeared in the corner. Now move the teddy bear to the other chair to create a clock. Move the clock to reveal another entrance. Turn small again and exit to the Tea Party Garden.
Tea Party Garden
When you enter, open the chest and hop down. Read the sign near the portrait a couple of times. You can sit in any of the chairs once, and 5 of them will yield very good items. The other two trigger battles that you may or may not wish to fight.
Now enter the door nearby that leads to the Bizarre Room. Now you're on the ceiling! Jump onto the table from the nearby ramp and light the candles to talk to the Cheshire Cat again. Down on the wall is a small latch that opens a hidden door. Jump through to the Queen's Court.
Open the nearby chest.
Now would be a good time to save.
Enter the Bizarre room again (right side up), and check the plant. You should be around level 13 if you want an easy boss battle. Go talk to the Chesire Cat. After he gives you his message ("the shadows are coming"), you will face the next and final boss of Wonderland.
After you defeat Trickmaster, Sora will unlock the world through the doorknob and you will learn Blizzard (unless you already learned it). You can now go back to the Save Point in the Rabbit Hole and leave the world.